The present invention relates to a vehicle suspension apparatus which can reduce rolling of a vehicle making a turn.
In order to reduce rolling of a vehicle body making a turn, the present applicant had previously proposed a vehicle suspension apparatus comprising fluid spring means inserted between respective wheels of a vehicle and a vehicle body; fluid supply means for supplying a fluid to the fluid spring means through supply control valves, respectively; fluid exhaust means for exhausting the fluid from the fluid spring means through exhaust control valves, respectively; communicating means for enabling and disabling communication between right and left fluid spring chambers of the vehicle; velocity detecting means for detecting a velocity of the vehicle; steering angle detecting means for detecting a steering angle; communication control means for disabling said communicating means when conditions are satisfied that the velocity detected by the velocity detecting means exceeds a preset velocity and the steering angle detected by the steering angle detecting means exceeds a preset steering angle and for enabling the communicating means when the conditions are not satisfied; and roll control means for supplying a preset amount of fluid to fluid spring chambers on the contracted side with respect to the roll direction and for exhausting a preset amount of fluid from fluid spring chambers on the stretched side when the conditions are satisfied.
In this apparatus, during a vehicle drive pattern wherein the vehicle velocity is increased from zero and returned to zero again while the steering angle is set above the preset steering angle and when the velocity detecting means detects that the velocity has exceeded the preset velocity, the communicating means is disabled by the communication control means and roll control is started by the roll control means. When the velocity becomes lower than the preset velocity, the communication control means enables the communicating means.
In such a drive pattern, due to the presence of suspension units mounted between the vehicle body and wheels, passengers experience centrifugal force sensations slightly later than the actual increase/decrease in velocity.
In this drive pattern, passengers feel different centrifugal force sensations when the vehicle velocity is increased or decreased. Note that when the velocity is increased, the communication control means disables the communicating means and the roll control means starts roll control, and when the velocity is decreased, the communication control means enables the communicating means. Because of this, riding comfort of passengers in the vehicle is impaired, leading to poor control results.